Methods and compositions for enhancing guar hydration rates and performing guar derivatization reactions

ABSTRACT

Methods are provided that include, but are not limited to, methods of treating guar splits comprising: exposing guar splits to a treatment chemical to create treated guar splits, wherein the treatment chemical comprises at least one treatment chemical selected from the group consisting of: an aqueous salt solution; a caustic solution, and a derivatizing agent; and grinding the treated guar splits to create ground, treated guar splits.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.12/550,116, which was filed on Aug. 28, 2009, and is titled “Methods andCompositions for Enhancing Guar Hydration Rates and Performing GuarDerivatization Reactions,” which is a continuation in part of U.S.patent application Ser. No. 11/035,305, which was filed on Jul. 13,2006, and is titled “Methods and Compositions for Enhancing GuarHydration Rates and Performing Guar Derivatization Reactions,” thedisclosures of which are incorporated herein by reference in theirentireties.

BACKGROUND OF THE INVENTION

The present invention relates to subterranean treatment fluids. Moreparticularly, the present invention relates to methods and compositionsfor enhancing guar hydration rates and performing guar derivatizationreactions.

Treatment fluids are used in a variety of operations and treatmentsperformed in oil and gas wells. Such operations and treatments include,but are not limited to, production stimulation operations, such asfracturing, and well completion operations, such as hydraulicfracturing, gravel packing and frac packing.

In hydraulic fracturing, a type of treatment fluid, referred to in theart as a fracturing fluid, is pumped through a well bore into asubterranean zone to be stimulated at a rate and pressure such thatfractures are formed or enhanced in a desired subterranean zone. Thefracturing fluid is generally a gel, emulsion, or foam that may comprisea particulate material often referred to as proppant. When used,proppant is deposited in the fracture and functions, inter alia, to holdthe fracture open while maintaining conductive channels through whichsuch produced fluids can flow upon completion of the fracturingtreatment and release of the attendant hydraulic pressure.

Gravel packing treatments are used, inter alia, to reduce the migrationof unconsolidated formation particulates into the well bore. In gravelpacking operations, particulates, referred to in the art as gravel aresuspended in a treatment fluid, which may be viscosified, and thetreatment fluid is pumped into a well bore in which the gravel pack isto be placed. As the particulates are placed in the zone, the treatmentfluid leaks off into the subterranean zone and/or is returned to thesurface. The resultant gravel pack acts as a filter to separateformation solids from produced fluids while permitting the producedfluids to flow into and through the well bore. While screenless gravelpacking operations are becoming more common, traditional gravel packoperations involve placing a gravel pack screen in the well bore andpacking the surrounding annulus between the screen and the well borewith gravel designed to prevent the passage of formation particulatesthrough the pack with produced fluids, wherein the well bore may beoriented from vertical to horizontal and may extend from hundreds tothousands of feet.

In some situations the processes of hydraulic fracturing and gravelpacking are combined into a single treatment to provide a stimulatedproduction and an annular gravel pack to prevent formation sandproduction. Such treatments are often referred to as “frac pack”operations. In some cases the treatments are completed with a gravelpack screen assembly in place with the hydraulic fracturing treatmentbeing pumped through the annular space between the casing and screen. Inthis situation the hydraulic fracturing treatment ends in a screen outcondition creating an annular gravel pack between the screen and casing.This allows both the hydraulic fracturing treatment and gravel pack tobe placed in a single operation. In other cases the fracturing treatmentmay be performed prior to installing the screen and placing a gravelpack.

A variety of methods are used to create the viscosified treatment fluidstypically used in subterranean operation. Generally, a polysaccharide orsynthetic polymer gelling agent is used to impart viscosity to thetreatment fluid to, among other things, enhance proppant or graveltransport and reduce fluid loss from the treatment fluid into theformation. Frequently, a crosslinking agent, such as a metal ion withorganic or inorganic counterion, organometallic or organic compound, isalso added to further enhance the viscosity of the fluid by coupling, or“crosslinking,” polymer molecules. The treatment fluid may also includeone or more of a variety of well-known additives, such as gelstabilizers, fluid loss control agents, clay stabilizers, bactericides,and the like.

Guar gum and guar derivatives are commonly used in the oilfield tomanufacture treatment fluids. Guar gum is typically prepared bymechanically and/or chemically treating guar beans to liberate the guarseed endosperm, or “guar splits,” from the beans. Guar splits primarilycomprise a polymannose backbone with galactose side chains and mannose,and contain a fair concentration of contaminates, such as cellulose,protein, and glycolipids. The guar splits are generally treated underhigh pressures and temperatures with chemicals, after which they aresubjected to multiple washings to remove impurities and salts (which arebyproducts of some of the treatments) from the splits. The treated andwashed splits are then ground and dried to yield derivatized guars.

The guar powders are typically dispersed into a water-based fluid, suchas a 2% KCl solution, and allowed time to hydrate. This dispersion maybe accomplished by adding the powdered guar directly to water, or byfirst creating a liquid slurry, or liquid gel concentrate (“LGC”), ofthe powder in a non-hydrating solvent, such as diesel. After hydration,the guar fluid is significantly higher in viscosity, making it possibleto transport high-density propping agents through pumping equipment andinto a subterranean formation.

Despite their widespread use, guar-based treatment fluids do have sometechnical disadvantages. For example, the time necessary for completehydration and/or viscosity generation for guar-based fluids may takeseveral minutes. This can be particularly inconvenient during on-the-flyfracturing applications. In order to successfully use guar-based fluidsin a continuous fashion requires the use of large volume (i.e., longresidence time) holding tanks to permit the hydration of the guar gum.In addition to requiring additional equipment at the well site, thislarge holding volume limits the ability to change fluid formulations inresponse to real-time pressure changes that may be measured during thefracturing treatment. Even the derivatization of the guar can provecostly and/or inconvenient, as the derivatization process typicallyrequires large reactors capable of handling dry materials to treat theguar splits, increasing the equipment expense necessary for creating theguar-based fluids.

SUMMARY OF THE INVENTION

The present invention relates to subterranean treatment fluids. Moreparticularly, the present invention relates to methods and compositionsfor enhancing guar hydration rates and performing guar derivatizationreactions.

In one embodiment, the present invention provides a method of treatingguar splits comprising: exposing guar splits to a treatment chemical tocreate treated guar splits, wherein the treatment chemical comprises atleast one treatment chemical selected from the group consisting of: anaqueous salt solution; a caustic solution, and a derivatizing agent; andgrinding the treated guar splits to create ground, treated guar splits.

In another embodiment, the present invention provides a method of usingguar splits comprising: providing ground guar splits that were exposedto at least one treatment chemical prior to the guar splits being groundand allowed to at least partially dry, wherein the at least onetreatment chemical is selected from the group consisting of: an aqueoussalt solution; a caustic solution, and a derivatizing agent; andhydrating the ground guar splits.

In another embodiment, the present invention provides a method of usingguar splits comprising: providing ground guar splits that were exposedto a treatment chemical comprising a salt solution prior to the guarsplits being ground and allowed to at least partially dry; and hydratingthe ground guar splits.

The features and advantages of the present invention will be readilyapparent to those skilled in the art upon a reading of the descriptionof the preferred embodiments that follows.

DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention relates to subterranean treatment fluids. Moreparticularly, the present invention relates to methods and compositionsfor enhancing guar hydration rates and performing guar derivatizationreactions.

In accordance with the teachings of the present invention, guar splitsare exposed to a treatment chemical and then ground and dried, forexample, ground and dried into a guar powder. According to someembodiments of the present invention, the treatment chemical maycomprise a salt, a caustic solution, a derivatizing agent, or acombination thereof. In embodiments in which guar splits are exposed toa treatment chemical comprising a salt, the salt may have the effect ofincreasing the hydration rate of the guar splits after they have beenground and allowed to dry. In embodiments in which the treatmentchemical comprises a caustic solution, the caustic solution may alsohave the effect of increasing the hydration rate of the guar splitsafter they have been ground and allowed to dry. In embodiments in whichthe treatment chemical comprises a derivatizing agent, the derivatizingagent may derivatize the treated guar, e.g., after the treated guar hasbeen ground and allowed to dry. In this fashion, the physical propertiesof guar gum created from the ground and dried guar splits may betailored without the use of extensive treatments and/or large equipmentexpense.

Of the many potential advantages of the methods of the presentinvention, one advantage may be that after guar splits have been treatedas disclosed herein, ground, and allowed to dry, it may take less timeto hydrate the resulting guar powder. This reduction in hydration timemay be associated with, among other things, less time lost waiting onhydration, and a reduced need for storage for ground and dried guar asit hydrates. In some cases, reduced guar hydration times allow guarpowder to be hydrated continuously rather than batch mixed many hours inadvance of when it will be used. Additionally, solutions that containre-hydrated guar powders made from guar splits that were treated inaccordance with some of the methods of the present invention, forexample guar splits that have been derivatized and exposed to a saltsolution before being ground, may have increased viscosity yield (i.e.,higher viscosity from a comparable amount of untreated guar splitstarting material).

According to some embodiments of the present invention, guar splits aretreated with a salt. The salt may be used alone, or may be combined withor used in conjunction with a caustic solution and/or a derivatizingagent. In exemplary embodiments, the salt is provided in an aqueous saltsolution. The salt solution may desirably have a higher saltconcentration than the internal salt concentration of the guar splitsthat are being treated. In exemplary embodiments, the salt present inthe salt solution includes an alkali metal (Group I) monovalent cation.In some embodiments, salts having multivalent, e.g., divalent,trivalent, and tetravalent, cations may be suitable. In someembodiments, treating guar splits with a salt comprising a multivalentcation may be less desirable, because multivalent cations may causeproblems later, when the treated guar splits are being processed. Ingeneral, the counterion of the salt used should be soluble in theaqueous fluid of the salt solution.

Salts that may be suitable for use in treating guar splits include, butare not limited to, sodium chloride, potassium chloride, lithiumchloride, potassium nitrate, sodium nitrate, bromides, nitrates, andbuffer salts such as acetates and carbonates, and combinations thereof.It is believed that treating guar splits with a treatment chemicalcomprising a salt may increase the hydration rate of guar powders thatare produced from the treated guar splits. In some embodiments, a saltsolution for treating guar splits may be made by mixing about equalvolumes of water and a saturated brine. In some embodiments, the saltsolution may have a salt concentration in the range of about 5% byweight of the solution to about the saturation point of the salt insolution. In some embodiments, the salt solution may have a saltconcentration in the range of about 15% by weight of the solution toabout the saturation point of the salt in solution.

Without wishing to be bound by theory, it is thought that when the guarsplits are exposed to a salt solution, because there is a lower saltconcentration naturally present inside the guar splits than in the saltsolution, water from the salt solution enters the guar splits byosmosis. It is also thought that salt from the salt solution migrateswith the water as it enters the guar splits, thereby increasing the saltconcentration inside the guars splits. Thus, when the treated guarsplits are removed from the salt solution, the interior of the guarsplits has a higher concentration of salt than before the guar splitswere treated with the salt. The time that the guar splits may be exposedto a salt solution may vary depending on the amount of guar splits, thevolume of a salt solution, the temperature, and pressure. In exemplaryembodiments, the guar splits are removed from the salt solution or theguar splits absorb substantially all of the salt solution before theguar splits take on a gelatinous quality.

After the guar splits have been removed from the treatment solution,they may or may not be washed to remove any treatment solution that isresidual on the surface of the guar splits. In some embodiments, guarsplits that have been exposed to a treatment chemical are washed beforebeing ground and allowed to dry. In embodiments in which guar splitshave been treated with salt solution to increase the hydration rate ofguar powder produced from the splits, the increased hydration rate maynot be significantly diminished by washing excess salt solution from thesurface of the splits prior to grinding. It is thought that washing saltsolution off the surface of the un-ground guar splits may not diminishthe hydration rate of guar powder produced from the splits, as the saltsthat are thought to be responsible for the increase in hydration ratehave already been imbibed into, i.e., are internal, to the splits priorto grinding.

In other embodiments, there is no washing step before grinding anddrying the guar splits. Such exposure to treatment chemicals withoutsubsequent washing may be used to enhance selected properties of theresulting guar gum. In some embodiments, it may be desirable not to washthe guar splits, or, if the guar splits are washed, to avoid prolongedwashing that would remove salt that has been imbibed into the interiorof the guar split during treatment with a salt solution. In someembodiments, after the guar splits have been removed from a treatmentsolution, and after an optional washing step if used, the guar splitsare ground. While grinding, the water in the interior of the guar splitsmay at least partially evaporate. The ground guar splits may then befurther dried.

In embodiments in which guar splits are treated with a salt solution,ground, and allowed to dry, although the ground guar splits no longercomprise a substantial portion of the water that was imbibed from thesalt solution, the ground guar splits have a higher internalconcentration of salt, because salt was imbibed into the interior of theguar splits during treatment and before grinding. When these ground guarsplits (e.g., guar split powder) are subsequently hydrated, hydrationmay progress more quickly than would hydration of guar splits that hadnot been treated.

In particular embodiments of the present invention, guar splits may betreated with a caustic solution to enhance the hydration rates of theresulting guar gum. Moreover, the addition of a caustic solution maymake the guar powder more brittle and thus more easily ground. Suitablecaustic solutions include, but are not limited to, sodium hydroxide,potassium hydroxide, and lithium hydroxide.

Contrary to common guar processing methods, in some embodiments, afterthe guar splits have been treated with the caustic solution, the splitsare not washed. Rather the treated splits are ground and dried with thecaustic solution still on the splits. It is thought that in somesituations, proteinaceous material that may be present in guar powderthat is used in a subterranean treatment fluid may result inconductivity loss in the subterranean formation. In some embodiments,when exposed to a caustic solution, the proteinaceous material mayhydrolyze and form salts that are soluble in water. Thus, by grindingthe guar splits with caustic solution still on the splits (i.e., notcompletely washed off), proteinaceous material that may be present inthe interior of the guar splits may hydrolyze when exposed to theresidual caustic solution during grinding. Thus, conductivity loss dueto proteinaceous material in the ground guar splits may be reduced. Inother embodiments, treated guar splits may be washed before grinding.

In other embodiments of the present invention, the guar splits may betreated with a derivatizing agent to derivatize the guar. Generally, thechoice of derivatizing agent may depend on the specific derivatizationdesired. Suitable derivatizing agents are electrophilic, organiccompounds capable of reacting with open sites along a polymer. Such opensites may be formed, for example, when the guar splits are ground. Insome embodiments, the derivatizing agent may include highly reactivecompounds that are reactive to free radicals. Suitable derivatizingagents include, but are not limited to, derivatives of acrylic acid,cationic salts of acrylic acid, acrylic acid esters, and acrylic acidamides. Other suitable derivatizing agents include epoxides, lactones,sultones, oxaphospholanes, alkyl halides, derivatives of quinone (suchas hydroquinone), triethanolamine, sodium bisulfite, and sodiumthiosulfate. With the benefit of this disclosure, one skilled in the artwill be aware of numerous other derivatizing agents suitable for use inthe present invention.

Contrary to common guar processing methods, in some embodiments, afterthe guar splits have been treated with a derivatizing agent, the splitsare not washed. Rather the treated splits are ground and dried with thetreatment chemical still on the splits. In addition to reducing the guarsplits to a powder, the grinding action of the process also creates anumber of open sites along the guar polymer. These sites are then freeto react with the derivatizing compound as described above. In thisfashion, chemical moieties can be grafted directly onto the polymerwithout the use of expensive reactor techniques.

Whether the chosen treatment chemical is a derivatizing agent, a causticsolution, or a salt solution alone or in combination with one of theforegoing, the treated guar splits are ground and allowed to dryfollowing the treatment. In some embodiments, the splits may be groundin a hammermill or a pulverizer. The splits are commonly ground to apowder, generally to a size of less than about 100 mesh, U.S. SieveSeries. Generally the ground splits are then dried to a moisture contentof less than about 20%. In some embodiments the ground splits are driedto a moisture content of less than about 12%. In some embodiments theground splits are dried using known flash drying methods. As will beappreciated by one skilled in the art, a large number of variations maybe affected in the grinding and drying of the guar splits withoutmaterially deviating from the scope and spirit of the present invention.

With the benefit of this disclosure, one of ordinary skill in the artwill be able to select guar splits that are appropriate for use in themethods of the present invention. Typically, guar splits are produced byseparating guar seed endosperms from guar beans. This may beaccomplished using a number of mechanical and/or chemical treatmentswell known in the art. One of ordinary skill in the art, with thebenefit of this disclosure, should be able to select an appropriatemethod of producing guar splits for use in accordance with the teachingsof the present invention.

In particular embodiments, a treated guar gelling agent of the presentinvention may be used in a treatment fluid for use in a subterraneanoperation, such as fracturing or gravel packing Such treatment fluidsinclude aqueous gels, foams, and emulsions. The aqueous gels aregenerally comprised of water and one or more gelling agents. Theemulsions may be comprised of two immiscible liquids such as an aqueousgelled liquid and a liquefied, normally gaseous fluid, such as nitrogen.In exemplary embodiments of the present invention, the treatment fluidsare aqueous gels comprised of water, a treated guar gelling agent forgelling the water and increasing its viscosity, and, optionally, acrosslinking agent for crosslinking the gel and further increasing theviscosity of the fluid. The increased viscosity of the gelled, or gelledand crosslinked, treatment fluid, inter alia, reduces fluid loss andallows the treatment fluid to transport significant quantities ofsuspended particulates. The water used to form the treatment fluid maybe fresh water, seawater, salt water, brine, or any other aqueous liquidthat does not adversely react with the other components.

In addition to the treated guar gelling agents of the present invention,other gelling agents may be used to further viscosify the treatmentfluids of the present invention. Suitable additional gelling agentsinclude hydratable polymers that contain one or more functional groupssuch as hydroxyl, carboxyl, sulfate, sulfonate, amino, or amide groups.Particularly useful are polysaccharides and derivatives thereof thatcontain one or more of the monosaccharide units galactose, mannose,glucoside, glucose, xylose, arabinose, fructose, glucuronic acid, orpyranosyl sulfate. Examples of natural hydratable polymers containingthe foregoing functional groups and units that are suitable for use inaccordance with the present invention include, but are not limited to,guar, guar derivatives, hydroxypropyl guar, carboxymethyl guar, xanthan,chitosan, scleroglucan, succinoglycan, starch, biopolymers, andhydroxyethyl cellulose. Hydratable synthetic polymers and copolymersthat contain the above-mentioned functional groups (e.g., hydroxyl,carboxyl, sulfate, sulfonate, amino, or amide groups) may also be used.Examples of such synthetic polymers include, but are not limited to,acrylamido-methyl-propane sulfonate (“AMPS”), polyacrylate,polymethacrylate, polyacrylamide, polyvinyl alcohol, andpolyvinylpyrrolidone. Generally, these various hydratable polymers andcopolymers contain functional groups that allow them to either hydrogenbond with themselves or adjacent polymers or copolymers, or to becrosslinked using an appropriate crosslinking agent.

In particular embodiments, the treatment fluids of the present inventionmay also include a crosslinking agent. Crosslinking agents typicallycomprise at least one ion that is capable of crosslinking at least twogelling agent molecules. Examples of suitable crosslinking agentsinclude, but are not limited to, N,N′-methylenebisacrylamide, boricacid, disodium octaborate tetrahydrate, sodium diborate, pentaborates,ulexite and colemanite, compounds that can supply zirconium IV ions(such as, for example, zirconium lactate, zirconium lactatetriethanolamine, zirconium carbonate, zirconium acetylacetonate,zirconium malate, zirconium citrate, and zirconium diisopropylaminelactate); compounds that can supply titanium IV ions (such as, forexample, titanium lactate, titanium malate, titanium citrate, titaniumammonium lactate, titanium triethanolamine, and titaniumacetylacetonate); aluminum compounds (such as, for example, aluminumlactate or aluminum citrate); antimony compounds; chromium compounds;iron compounds; copper compounds; zinc compounds; or a combinationthereof. An example of a suitable commercially available zirconium-basedcrosslinker is “CL-24” available from Halliburton Energy Services, Inc.,Duncan, Okla. An example of a suitable commercially availabletitanium-based crosslinking agent is “CL-39” available from HalliburtonEnergy Services, Inc., Duncan, Okla. Suitable crosslinking agentsgenerally are present in the viscosified treatment fluids of the presentinvention in an amount sufficient to provide, inter alia, the desireddegree of crosslinking between gelling agent molecules. In someembodiments of the present invention, the crosslinking agent may bepresent in an amount in the range from about 0.001% to about 10% byweight of the water in the treatment fluid. In some embodiments of thepresent invention, the crosslinking agent may be present in an amount inthe range from about 0.01% to about 1% by weight of the water in thetreatment fluid. Individuals skilled in the art, with the benefit ofthis disclosure, will recognize the exact type and amount of crosslinkerto use depending on factors such as the specific gelling agent, desiredviscosity, and formation conditions.

The gelled or gelled and crosslinked treatment fluids may also includeinternal delayed gel breakers such as enzyme, oxidizing, acid buffer, ortemperature-activated gel breakers. The gel breakers cause the viscoustreatment fluids to revert to relatively thin fluids that can beproduced back to the surface after they have been used to, for example,place particulates in subterranean fractures. The gel breaker used istypically present in the treatment fluid in an amount in the range offrom about 1% to about 5% by weight of the gelling agent. The treatmentfluids may also include one or more of a variety of well-knownadditives, such as gel stabilizers, fluid loss control additives, claystabilizers, bactericides, and the like.

Generally, the treatment fluids of the present invention are suitablefor use in hydraulic fracturing, frac-packing, and gravel packingapplications. In exemplary embodiments of the present invention wherethe treatment fluids are used to carry particulates, the particulatesare generally of a size such that formation fines that may migrate withproduced fluids are prevented from being produced from the subterraneanzone. Any suitable particulate may be used, including graded sand,bauxite, ceramic materials, glass materials, walnut hulls, polymerbeads, and the like. Generally, the particulates have a size in therange of from about 4 to about 400 mesh, U.S. Sieve Series. In someembodiments of the present invention, the particulates are graded sandhaving a particle size in the range of from about 10 to about 70 mesh,U.S. Sieve Series. In particular embodiments of the present invention,the particulates may be at least partially coated with a curable resin,tackifying agents, or some other flowback control agent or formationfine control agent.

To facilitate a better understanding of the present invention, thefollowing examples of preferred embodiments are given. In no way shouldthe following examples be read to limit or define the scope of theinvention.

EXAMPLES Example 1

The effect of various non-covalent additives was evaluated by adding to200 grams of guar bean splits various additives as listed in Table 1.The mixtures as described in Table 1 were then heated at 150° F. in aroller oven for two hours and then ground with a pulvet grinder, thendehydrated in a vacuum oven to create dehydrated guar flour. Finally,the ground, dehydrated guar flour was stirred into 120 ML of Duncan,Okla. tap water (“dtw”), and the viscosity was measured over time usinga Brookfield viscometer (made by PVS, Middleboro, Mass.). The dataclearly show that treating guar splits with additives can affect theviscosifying abilities of a resulting guar powder.

TABLE 1 Treatment formula 20 g NaOH 20 g NaOH 20 g NaOH 30.85 g KOHbefore Control 10 g urea 16.95 g LiCl 23.37 gNaCl 30 g KCl 30 g KClgrinding 200 g 120 cc dtw 120 cc dtw 120 cc dtw 120 cc dtw 120 cc dtw120 cc dtw and splits 200 g splits 200 g bean 200 g bean 200 g bean 200g bean 200 g bean drying viscosity viscosity viscosity viscosityviscosity viscosity viscosity TIME (cP) (cP) (cP) (cP) (cP) (cP) (cP) 28.95 7.1 10.54 10.7 13.2 16.35 15.05 3 10.7 8.8 12.37 14.8 15.05 19.118.8 4 11.75 10.1 14.35 17.6 18.3 23.85 23.45 5 12.7 11.85 16.1 20.220.6 26.55 27.5 10 16.6 18.4 22.65 28 29.3 33.25 37.2 20 19.45 22.9 27.432.05 32.6 36.8 40.05 30 21.45 24.95 29.55 33.25 33.8 37.9 40.95 60 24.227.7 32.41 34.6 36.05 40.23 42.35

Example 2

To 100 g of guar bean splits was added 60 g of water, 10 g of NaOH, and15 g of KCl. Then one of the following derivatizing agents was added:hydroquinone (0.5 g), triethanolamine (0.62 g), sodium bisulfite (0.5 g)and sodium thiosulfate (0.5 g). Two samples served as control using thesame recipe with the exception of the addition of the derivatizingagent. These were identical with the exception of maintaining one in anoxygen free environment.

To correct for moisture weight, the samples were analyzed for watercontent. For hydration testing, the sample effective weight ofpolysaccharide was added to 250 mL of tap water, 5 g KCl, then the pHwas adjusted to 7-7.5 at a temperature of 75-77° F. The change inviscosity versus time was measured until the change was constant. Twohours was arbitrarily chosen as a time where 100% hydration wasattained. To correct for variations in particle sizes, the groundparticles were sieved and particles retained on the same screen wereused for the hydration study described in the above paragraph.

To verify the derivatizing agent had been covalently attached to theguar, the sample was subjected to continuous extraction using a Soxhletapparatus and dichloromethane. Upon evaporation of the residue, thesample was found only to contain a trace amount of guar bean oil and noexcess derivatizing agent or reaction derivatives. This resultdemonstrates the fate of the derivatizing agent necessarily had to havereacted with the guar.

The data clearly show that treating guar splits with additives canaffect the viscosifying abilities of a resulting guar powder.

TABLE 2 oxygen free sodium sodium formula control control hydroquinonetriethanolamine bisulfite thiosulfate TIME viscosity viscosity viscosityviscosity viscosity viscosity (min) (cP) (cP) (cP) (cP) (cP) (cP) 2 8.46.2 5.2 8.2 6.7 7.4 3 10.9 8 6 8.9 9.2 8.3 4 12.5 9.4 6.8 9.6 10.8 8.7 513.9 10.7 7.2 9.9 12.2 9.7 10 17.5 15 8.4 10.8 15.9 10 20 19.1 16.5 911.2 17.5 10.2 30 19.8 17.2 9.5 11.4 18.2 10.2 60 20.1 17.7 9.8 11.618.5 10.2 120 20.9 18.9 10.4 11.6 18.6 10.4

Therefore, the present invention is well adapted to attain the ends andadvantages mentioned as well as those that are inherent therein. Theparticular embodiments disclosed above are illustrative only, as thepresent invention may be modified and practiced in different butequivalent manners apparent to those skilled in the art having thebenefit of the teachings herein. Furthermore, no limitations areintended to the details of construction or design herein shown, otherthan as described in the claims below. It is therefore evident that theparticular illustrative embodiments disclosed above may be altered ormodified and all such variations are considered within the scope andspirit of the present invention. While compositions and methods aredescribed in terms of “comprising,” “containing,” or “including” variouscomponents or steps, the compositions and methods can also “consistessentially of” or “consist of” the various components and steps. Allnumbers and ranges disclosed above may vary by some amount. Whenever anumerical range with a lower limit and an upper limit is disclosed, anynumber and any included range falling within the range is specificallydisclosed. In particular, every range of values (of the form, “fromabout a to about b,” or, equivalently, “from approximately a to b,” or,equivalently, “from approximately a-b”) disclosed herein is to beunderstood to set forth every number and range encompassed within thebroader range of values. Also, the terms in the claims have their plain,ordinary meaning unless otherwise explicitly and clearly defined by thepatentee. Moreover, the indefinite articles “a” or “an”, as used in theclaims, are defined herein to mean one or more than one of the elementthat it introduces. If there is any conflict in the usages of a word orterm in this specification and one or more patent or other documentsthat may be incorporated herein by reference, the definitions that areconsistent with this specification should be adopted.

What is claimed is:
 1. A method of treating guar splits comprising:exposing guar splits to a derivatizing agent to create treated guarsplits, wherein the derivatizing agent is selected from the groupconsisting of: a cationic salt of acrylic acid, an acrylic acid ester,an oxaphospholane, a derivative of quinone, triethanolamine, sodiumbisulfite, and sodium thio sulfate; grinding the treated guar splitswithout first washing the treated guar splits to create ground, treatedguar splits; and drying the ground, treated guar splits.
 2. The methodof claim 1 wherein the step of grinding the treated guar splitscomprises grinding the treated guar splits in a hammermill or apulverizer.
 3. The method of claim 1 wherein during the step of grindingthe treated guar splits, the treated guar splits are ground to a size ofless than about 100 mesh, U.S. Sieve Series.
 4. The method of claim 1wherein during the step of drying the ground, treated guar splits, theground, treated guar splits are dried to a moisture content of less thanabout 12%.
 5. The method of claim 1 wherein the step of drying theground, treated guar splits comprises flash drying the ground, treatedguar splits.